Augustine: Earlier Writings (continued)
to that. Even if I did perceive numbers with the bodily senses I could not in the same way perceive their divisions and relations. By referring to these mental operations I show anyone to be wrong in his counting who gives a wrong answer when he adds or subtracts. Moreover, all that I contact with a bodily sense, such as this sky and this earth and whatever I perceive to be in them, I do not know how long it will last. But seven and three make ten not only now but always. In no circumstances have seven and three ever made anything else than ten, and they never will. So I maintain that the unchanging science of numbers is common to me and to every reasoning being.
22. Aug.—I do not deny that your reply is certainly most true. But you will easily see that numbers are not conveyed to us by our bodily senses if you consider that the value of every number is calculated according to the number of times it contains the number one. For example, twice one is called two; thrice one is called three; ten times one is called ten, and every number receives its name and its value according to the number of times it contains the number one. Whoever thinks with exactitude of unity will certainly discover that it cannot be perceived by the senses. Whatever comes into contact with a bodily sense is proved to be not one but many, for it is corporeal and therefore has innumerable parts. I am not going to speak of parts so minute as to be almost unrealizable; but, however small the object may be, it has at least a right-hand part and a left-hand part, an upper and a lower part, a further and a nearer part, one part at the end and another at the middle. W' e must admit that these parts exist in any body however small, and accordingly we must agree that no corporeal object is a true and absolute unity. And yet all these parts could not be counted unless we had some notion of unity. When I am seeking unity in the corporeal realm and am at the same time certain that I have not found it, nevertheless I know what I am seeking and failing to find, and I know that I cannot find it, or rather that it does not exist among corporeal things. When I know that no body is a unity, I know what unity is. If I did not know what unity is, I could not count the plurality of parts in a body. However
I have come to know unity, I have not learned it from the bodily senses, for by them I can know only corporeal objects, and none of them, as we have proved, is a true unity. Moreover, if we do not perceive unity with any bodily sense, neither do we perceive any number, of the kind at any rate which we discern with the intellect. For there is none of them which is not a